This invention relates to improvement in a brake pressure control valve for use in a vehicle.
Various types of brakes utilizing hydraulic pressure are used in vehicles but, in such brakes, when hydraulic pressure generated by a brake pedal depressed by a driver is transmitted equally to the front and rear wheel brakes, the rear wheels will skid substantially prior to the point at which the front wheels begin to skid. This condition is very dangerous since it will sometimes cause so-called fish-tailing of the vehicle.
In preventing such shortcomings caused by change in the weight distribution of the vehicle between the static condition and the rapidly decelerated condition, hydraulic pressure control valves of the type utilizing an inertia valve which actuates in response to the inertia force acting on applying brake have been interposed between the master cylinder and rear wheel brake cylinders to reduce hydraulic pressure transmitted to the rear wheel brake cylinders with respect to the front wheel brake cylinders.
While, in the hydraulic pressure control valve of the aforementioned type, it has sometimes been experienced that it is very difficult to bleed or to expel any included air from hydraulic braking system incorporating the control valve completely since the inertia valve will tend to close under the influence of high speed liquid flow flowing through the system in the bleeding operation.